The present invention relates to a coyping machine. More particularly this invention concerns a paper cassette for an electrostatic copier.
An electrostatic copying machine normally has a paper-supply location where a stack of copy sheets is held. A paper-advance element is displaceable toward and away from this location to move the uppermost sheet off the stack of copy sheets and advance it to the location where an electrostatic or other copy is made on the sheet.
It is known to provide such a machine with a paper-holding cassette of box shape which serves to hold the stack of paper copy sheets in the machine at the paper-supply location. Such a cassette greatly eases loading and unloading of the machine, and makes it possible very rapidly to change the type of copy sheet or paper being used.
It is frequently desired to feed a single extra sheet into the machine so as to form a copy on this extra single sheet. This is frequently done to copy on the back of a previously made copy, to copy on letterhead, on an office form, or on a paper of a particular color. In order to avoid the necessity of having to reload the entire machine, it is known to provide a copying apparatus with a separate feed mechanism that can receive this extra copy sheet and feed it to the paper-advance element. Thus the user need merely slide the extra sheet into a slot normally provided on the machine above the paper-supply location so as to make a copy on this extra sheet.
The above-described system has a considerable disadvantage that it greatly adds to the complexity of the copier. This extra mechanism increases the possibility of breakdown of the machine, increases the size of the machine, and makes the machine more expensive.